Hi,

This is my first post although I have been following Hacker News for years.

I have been building something similar except not for Minecraft but hiking maps on mobile (Android). This is my app: https://play.google.com/store/apps/details?id=com.chessvorte...

I combine OpenStreetMap data for routes, satellite data from Sentinel-2 and Copernicus DEM GLO-30 for heights, resolution is around 10m/pixel for image and 30m for heights - those are the highest resolution datasets I can legally redistribute, although I am also including what I call hi-res maps building for some countries (USA, France, Italy, Switzerland, Austria, Romania) which has image resolution at 1.5m/pixel instead of 10m.

I could have used higher resolution for hi-res maps, data is available at precision like 30-50cm/pixel but this being a mobile app I needed to consider storage for a map on mobile, at hi-res a 10x10 km squared area takes around 25MB.

The idea for this came from my own hiking trips, in many mountains there is not so good internet connection, so I can build an offline map beforehand and in terrain I can use this to see where I am in 3D - and just use the phone GPS for location, no data needed.

For building the map packages I have setup a linux server that combines all 3 data sources (OpenStreetMap, Sentinel-2, Copernicus GLO-30) so once an area is chosen it can build it in like 1-3 minutes. Since all OSM endpoints are giving lots of timeouts I setup a local OSM mirror with the data that I need - takes around 50GB of storage for the whole world data and I have a script that updates it weekly.

Coming back to the original post, seeing 1:1 ratio of Switzerland made my heart stop for a bit, then I realized it's 1m resolution. Switzerland was also my first choice for hi-res data, they provide good accurate image and height datasets. Pretty cool all this Minecraft voxel rendering, I intend to see how it would look in my own app.